Re: [PATCH v2 3/8] efi: Decode IA32/X64 Processor Error Info Structure

From: Borislav Petkov
Date: Tue Feb 27 2018 - 09:26:04 EST


On Mon, Feb 26, 2018 at 01:38:59PM -0600, Yazen Ghannam wrote:
> From: Yazen Ghannam <yazen.ghannam@xxxxxxx>
>
> Print the fields in the IA32/X64 Processor Error Info Structure.
>
> Based on UEFI 2.7 Table 256. IA32/X64 Processor Error Information
> Structure.
>
> Signed-off-by: Yazen Ghannam <yazen.ghannam@xxxxxxx>
> ---
> Link:
> https://lkml.kernel.org/r/20180223200333.6410-4-Yazen.Ghannam@xxxxxxx
>
> v1->v2:
> * Add parantheses around "bits" expression in macro.
> * Fix indentation on multi-line statements.
>
> drivers/firmware/efi/cper-x86.c | 53 +++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 53 insertions(+)
>
> diff --git a/drivers/firmware/efi/cper-x86.c b/drivers/firmware/efi/cper-x86.c
> index 9da0d981178f..417bd4e500a7 100644
> --- a/drivers/firmware/efi/cper-x86.c
> +++ b/drivers/firmware/efi/cper-x86.c
> @@ -3,15 +3,28 @@
>
> #include <linux/cper.h>
>
> +#define INDENT_SP " "

That's just silly.

> +
> /*
> * We don't need a "CPER_IA" prefix since these are all locally defined.
> * This will save us a lot of line space.
> */
> #define VALID_LAPIC_ID BIT_ULL(0)
> #define VALID_CPUID_INFO BIT_ULL(1)
> +#define VALID_PROC_ERR_INFO_NUM(bits) (((bits) & GENMASK_ULL(7, 2)) >> 2)
> +
> +#define INFO_VALID_CHECK_INFO BIT_ULL(0)
> +#define INFO_VALID_TARGET_ID BIT_ULL(1)
> +#define INFO_VALID_REQUESTOR_ID BIT_ULL(2)
> +#define INFO_VALID_RESPONDER_ID BIT_ULL(3)
> +#define INFO_VALID_IP BIT_ULL(4)
>
> void cper_print_proc_ia(const char *pfx, const struct cper_sec_proc_ia *proc)
> {
> + int i;
> + struct cper_ia_err_info *err_info;
> + char newpfx[64];
> +
> printk("%sValidation Bits: 0x%016llx\n", pfx, proc->validation_bits);
>
> if (proc->validation_bits & VALID_LAPIC_ID)
> @@ -22,4 +35,44 @@ void cper_print_proc_ia(const char *pfx, const struct cper_sec_proc_ia *proc)
> print_hex_dump(pfx, "", DUMP_PREFIX_OFFSET, 16, 4, proc->cpuid,
> sizeof(proc->cpuid), 0);
> }
> +
> + snprintf(newpfx, sizeof(newpfx), "%s%s", pfx, INDENT_SP);
> +
> + err_info = (struct cper_ia_err_info *)(proc + 1);
> + for (i = 0; i < VALID_PROC_ERR_INFO_NUM(proc->validation_bits); i++) {
> + printk("%sError Information Structure %d:\n", pfx, i);
> +
> + printk("%sError Structure Type: %pUl\n", newpfx,
> + &err_info->err_type);

That dumps a GUID - how do I find out what type that GUID refers to?

> +
> + printk("%sValidation Bits: 0x%016llx\n",
> + newpfx, err_info->validation_bits);

As before, no need for those.

> +
> + if (err_info->validation_bits & INFO_VALID_CHECK_INFO) {
> + printk("%sCheck Information: 0x%016llx\n", newpfx,
> + err_info->check_info);
> + }
> +
> + if (err_info->validation_bits & INFO_VALID_TARGET_ID) {
> + printk("%sTarget Identifier: 0x%016llx\n",
> + newpfx, err_info->target_id);
> + }
> +
> + if (err_info->validation_bits & INFO_VALID_REQUESTOR_ID) {
> + printk("%sRequestor Identifier: 0x%016llx\n",
> + newpfx, err_info->requestor_id);
> + }
> +
> + if (err_info->validation_bits & INFO_VALID_RESPONDER_ID) {
> + printk("%sResponder Identifier: 0x%016llx\n",
> + newpfx, err_info->responder_id);
> + }

Those look like would need an additional decoding. Can we do that here
too?

> +
> + if (err_info->validation_bits & INFO_VALID_IP) {
> + printk("%sInstruction Pointer: 0x%016llx\n",
> + newpfx, err_info->ip);

The only thing that makes sense so far.

> + }
> +
> + err_info++;
> + }

Also, it is worth checking how much duplication there is with
drivers/firmware/efi/cper-arm.c and unifying the common pieces into
functions in cper-common.c or so.

--
Regards/Gruss,
Boris.

SUSE Linux GmbH, GF: Felix ImendÃrffer, Jane Smithard, Graham Norton, HRB 21284 (AG NÃrnberg)
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